Introduction And Importance: Joubert syndrome (JS) is defined by the characteristic set of cerebellum and midbrain abnormalities that communally result in the indicative "molar tooth sign" on the axial MRI report. The incidence of estimated to be from 1:80,000 to 1:100,000.
Case Presentation: Clinical features can be noticed shortly after birth that includes hypotonia episodic tachypnea and apnea that may be followed by developmental delays and speech apraxia. Polydactyly, cleft lip or palate, tongue abnormalities, hypotonia, encephalocele, meningocele, hydrocephalus, kidney problems, pituitary abnormality, and autistic-like behavior are the other deformities that can be seen with JS. Seizures may also occur. Motor disability and mental health range from mild to severe forms.
Clinical Discussion: Treatment for JS is symptomatic and supportive. The prognosis depends on cerebellar vermis development.
Conclusion: JS can be missed if special attention were not given to radiological findings.
Joubert syndrome is a rare autosomal recessive disorder characterized by the presence of the molar tooth sign on imaging. We report the case of a 5-year-old girl diagnosed with Joubert syndrome during the investigation of chronic vomiting. The patient presented with neuropsychomotor delay, a history of neonatal respiratory disorders, and hydrocephalus treated with a ventriculoperitoneal shunt.
Tubulin polyglutamylation is a posttranslational modification that occurs primarily along the axoneme of cilia. Defective axoneme polyglutamylation impairs cilia function and has been correlated with ciliopathies, including Joubert Syndrome (JBTS). However, the precise mechanisms regulating proper axoneme polyglutamylation remain vague.
Neurogenetics Research Center, Fondazione Istituto Neurologico Nazionale C Mondino Istituto di Ricovero e Cura a Carattere Scientifico, Pavia, Lombardia, Italy
Joubert syndrome (JS) is an inherited neurodevelopmental ciliopathy with wide clinical and genetic heterogeneity, whose paradigmatic sign is a peculiar cerebellar and brainstem malformation known as the 'molar tooth sign'. Recessive pathogenic variants in the gene are associated with hydrolethalus syndrome (HLS), a severe disorder characterised by multiple developmental defects leading to intrauterine or perinatal death. However, biallelic variants were also reported in three individuals with JS.
Ciliopathies are a diverse group of disorders resulting from abnormalities in the development or function of multiple organs. While significant research has clarified the role of the primary cilium in transducing numerous signalling pathways, elucidating causes of neuronal and skeletal development disorders, the origins of other ciliopathy-related conditions, such as hepatic fibrocystic diseases, remain elusive. Additionally, attempts to correlate specific ciliary proteins with distinct phenotypes have been largely unsuccessful due to the variable and overlapping symptoms of ciliopathies.
- Joubert syndrome and related disorders (JSRD) are complex and present diagnostic challenges due to their diverse clinical features, making neuroimaging essential for accurate diagnosis.
- Key neuroimaging techniques like MRI and CT can reveal significant abnormalities, including the "molar tooth sign," cerebellar vermal agenesis, and other neuroanatomical differences.
- Effective diagnosis and management of JSRD require a combination of clinical assessments, neuroimaging results, and collaboration among different medical specialists to address the various symptoms and complications.
